HP StorageWorks Enterprise File Services WAN Accelerator Deployment Guide (November 2005)

HP EFS WAN ACCELERATOR DEPLOYMENT GUIDE 63
7 - WCCP DEPLOYMENTS
 Unicast (User Datagram Protocol Packets). The HP EFS WAN
Accelerator is configured with the IP address of each router. If additional
routers are added to the service group, they must be added on each HP
EFS WAN Accelerator.
 Multicast. The HP EFS WAN Accelerator is configured with a multicast
group. If additional routers are added, you do not need to add or change
configuration settings on the HP EFS WAN Accelerators.
All Transmission Control Traffic (TCP) traffic is redirected by default. You can
configure specific source or destination ports to be redirected. For detailed
information, see “TCP Port Redirection” on page 77.
For other types of redirection filtering such as the Internet Protocol (IP)
address, you configure Access Control Lists (ACLs) on the routers and add it
to the service group. For detailed information, see “Specific Traffic
Redirection” on page 78.
Traffic is redirected using one of the following schemes:
 gre (Generic Routing Encapsulation). Each data packet is encapsulated
in a GRE packet with the HP EFS WAN Accelerator IP address configured
as the destination. This scheme is applicable to any network.
 l2 (Layer-2). Each packet Media Access Control (MAC) address is
rewritten with an HP EFS WAN Accelerator MAC address. This scheme is
possible only if the HP EFS WAN Accelerator is connected to a router at
Layer-2.
 either. The either value uses l2 (Layer-2) first—if Layer-2 is not
supported, gre is used.
You can load-balance using WCCP. Traffic is redirected based on a hashing
scheme and the weight of the HP EFS WAN Accelerators. You can hash on a
combination of the source IP address, destination IP address, source port, or
destination port. The default weight is based on the HP EFS WAN Accelerator
model number. (The weight is heavier for models that support more
connections.) You can modify the default weight. For detailed information, see
“Load Balancing” on page 78.
You can also provide failover support using WCCP. In a failover
configuration, the HP EFS WAN Accelerators periodically announce
themselves to the routers. If an HP EFS WAN Accelerator fails, traffic is
redirected to the working HP EFS WAN Accelerators. To configure failover
support where the passive HP EFS WAN Accelerator takes over if there is a
failure in the active HP EFS WAN Accelerator, you simply configure the
weight for the backup HP EFS WAN Accelerator to be 0. For detailed
information, see “Failover Support” on page 79.
Basic Steps The following steps summarize how to configure WCCP on a client-side HP
EFS WAN Accelerator with an out-of-path server-side HP EFS WAN
Accelerator.